Nut crimping tool

ABSTRACT

A motor driven tool provided with a rotatable socket for threading a nut upon a bolt and having clamping jaws for crimping the nut in place on the bolt, the clamping jaws being actuated by axial movement of an encircling jaw cup to which axial movement is imparted by threads which are driven from a motor driven tool through the medium of planet gears so that the socket will first torque the nut on the bolt and the jaw cup will then move against the jaws to engage and radially clamp the nut upon the bolt.

O United States Patent [151 3,653,802 Weiss [45] A r. 4 1972 [54] NUT CRIMPING TOOL Primary ExaminerThomas H. Eager [72] Inventor. 32:5:- vzrgeis-oglgzlss, 274 Vine Street, Atmmey R H Galbreath [22] Filed: Nov. 18, 1970 [57] ABSTRACT [21] Appl. No.: 90,566 A motor driven tool provided with a rotatable socket for threading a nut upon a bolt and having clamping jaws for crimping the nut in place on the bolt, the clamping jaws being actuated by axial movement of an encircling jaw cup to which axial movement is imparted by threads which are driven from [58] Field of Search ..29/20O R, 200 B, 240, 208 D a motor driven tool through the medium of planet gears so 5 6] References Cited that the socket will first torque the nut on the bolt and the jaw cup will then move against the jaws to engage and radially UNITED STATES PATENTS Clamp the nu! p the bolt- 3,479,714 1 ill 969 Allsop ..29/200 R 8 Claims, 8 Drawing Figures Patented April 4, 1972 4 Sheets-Sheet 1 Q aw wm N m nm m m E V N 1 [on 11 flwm? Mass Wi 0 I Patented April 4, 1972 4 Sheets-Sheet 2 GEM INVENTOR ion :21 flh/P/m? #4758 1 fl arriy Patented April 4, 1972 Iii NUT CRIMPING TOOL This invention relates to a tool for tightening and crimping a nut upon a threaded bolt for the purpose of locking the nut both to the bolt and to the work being accomplished. Tools and adapters for tools for this general purpose are at present on the market such as shown in prior U.S. Pat. Nos. 2,403,675; 3,122,948; 3,329,000; 3,4l0,l28; 3,478,564; 3,479,714.

These prior tools are subject to objections for various reasons, some require two independent tools, one for torquing the nut in place on the bolt and one for crimping the torqued nut in final position. Others must exert a tension or pull upon the bolt to accomplish the crimping action. This results in complicated mechanisms and often causes damage or breakage of the smaller bolts. Still others attempt to impart the crimping force directly from a rotating input tool which is often insufficient to develop the necessary crimping force upon the larger bolts and nut combinations.

The principal object of the present invention is to provide a single, relatively simple, highly efficient, self-contained tool which will, with a single application of power: match the nut to the bolt; rotate the nut into tight engagement with the work; and then radially crimp the torqued nut to simultaneously increase its frictional engagement with both the bolt and the work.

Another object is to provide a tool of the above type which will apply no pulling stresses on, or require any attachment to, the bolt, per se, so that bolt damage and other resulting complications will be eliminated.

Still another object is to provide a crimping tool which will automatically shift to a crimping position, when the nut has been torqued in place, to simultaneously apply both a final torquing and a crimping action upon the nut.

A further object is to so construct the tool that it can be quickly and easily lifted from a completely installed nut and immediately placed in working position on a second successive bolt and nut combination without loss of time and labor.

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy and efficiency. These will become more apparent from the following description.

In the following detailed description of the invention, reference is made to the accompanying drawings which form a part hereof. Like numerals refer to like parts in all views of the drawings and throughout the description.

In the drawings:

FIG. 1 is an enlarged longitudinal axial section, partially in elevation, through the nut crimping tool of this invention;

FIG. 2 is an end elevational view of the forward or output extremity of the improved tool;

FIG. 3 is a lateral cross section thereof taken on the line 3- 3, FIG. 1;

FIG. 4 is a similar cross section taken on the line 44, FIG. 1;

FIG. 5 is a cross section taken on the line 5-5, FIG. 1; FIG. 6 is an end elevational view of the rear or input extremity of the improved nut crimping tool;

FIG. 7 is a detail view illustrating a type of nut A, to which this invention is applicable, applied to a conventional bolt B and acting to clamp work pieces C together, with the relative position of the tool thereon shown in broken line; and

FIG. 8 illustrates the appearance of the nut of FIG. 7 after it has been crimped by the crimping tool of this invention.

The nut A is provided with a cylindrical crimpable skirt D and both the nut and its skirt are internally threaded to receive the threads of the bolt B. The skirt is an integral part of the nut.

The overall size of the improved tool will vary in correspondence with the sizes of the bolt and nut combinations upon which it is to be used. The drawing submitted shows the tool enlarged approximately 1% times over the size it would be in actual practise on a 7/16 inch diameter bolt.

STRUCTURE As illustrated the invention employs an elongated cylindrical housing 10 externally threaded at its rear extremity, as indicated at 11, to receive a cup-shaped housing cap 12 which can be locked upon the housing 10 by means of suitable set screws 13. The forward extremity of the housing 10 is closed by a unitary end wall 14 which is axially drilled to receive a shank portion 15 formed on the rear extremity of a nut socket member 16, to be later described. The nut socket member 16 is removably held in place by means of a retaining pin 17 passing diametrically through the housing 10, the end wall 14 and the shank 15. The retaining pin is removably held in place by means of a resilient rubber O-ring 18 positioned in a suitable circumferential ring groove which surrounds the forward extremity of housing 10 in the plane of the retaining pin 17 The rear extremity of the housing 10 is rotatably closed by means of bearing plate 19 which rides between a first annular thrust bearing 20, concentrically positioned between the rear extremity of the housing 10 and the plate 19, and a second annular thrust bearing 21, positioned concentrically between the plate 19 and the housing cap 12. The bearing plate 19 is concentrically secured, by means of suitable set screws 23, to the rear extremity of a cylindrical sleeve 22 concentrically positioned within the housing 10. The bearing plate 19 and the sleeve 22 are suitably socketed to receive the respective shafts of three planet gears 24 which mesh with the teeth of a ring gear 25 which are internally and concentrically formed in the rear extremity of the housing 10.

The planet gears 24 are positioned about, and mesh with, a sun gear 26 the teeth of which are formed on a tubular, axially positioned, clutch shaft 27 the rear extremity of which is provided with a clutch disc 28 to be later described.

The forward portion of the sleeve 22 is provided with internal threads 29 which threadably engage external threads 30 formed on a tubular drive fitting 31 which is provided with a forward annular flange 32 which can be brought into engagement with the forward extremity of the sleeve 22. Four similar compressing rods 33 are keyed, as indicated at 34, in the flange 32, of the drive fitting 31 and project slidably forward in parallel relation through the end wall 14 in uniform circumferentially spaced relation about the nut socket member 16. The forward extremities of the compressing rods 33 are keyed, as shown at 36, in suitable receiving-sockets in the rear extremity of a cup-shaped jaw cup 37 which surrounds the forward extremity of the socket member 16.

The forward extremity of the output socket member 16 is provided with a circular axial bolt socket 38 to receive the extremity of the bolt to be worked upon and the bolt socket is counter broached to form a nut socket 39 having a shape (usually hexagonal) to receive the nut to be worked upon.

The nut socket member 16 is also provided with an external circumferential latching groove 40 designed to maintain four similar crimping jaws 41 in place thereon. The jaws are formed with axially extending latch projections 42 at their rear extremities which are maintained in engagement with the latching groove 40 by a resilient metallic spring ring 43 which surrounds the plurality of jaws adjacent their rear extremities and acts to flare the forward extremities thereof at an outward angle against an inclined inner conical surface 44 formed in the forward lip of the jaw cup 37 as shown in FIG. 1. A nut-indenting edge 45 projects radially inward from the forward extremity of each jaw to engage and indent the not being worked upon when the jaw cup 37 is forced forwardly on the inclined crimping jaws 41.

Torque is applied to the tool by inserting the shank of any conventional reversable pneumatic or electric motor tool element in an input socket element 46 which is axially journaled in suitable conventional anti-friction bearings 47 in the housing cap 12. The rear extremity of the input socket element 46 is provided with a tool receiving socket 56.

The forward extremity of the input socket element 46 terminates in a second clutch disc 48 which axially aligns with the first clutch disc 28 on the tubular clutch shaft 27 of the sun gear 26.

The two clutch discs 28 and 48 are each provided with an annular set of radial, interengaging, overriding teeth 49 and 50, respectively. The sides of the teeth of each set are respectively inclined, as illustrated, so that when the input socket element 46 is rotated to the right, the two sets of teeth will interlock to simultaneously rotate the sun gear 26 to the right and, when the socket element 46 is rotated to the left, the second clutch disc 48 may be shifted rearwardly by the interaction of the teeth-inclines to allow the teeth 50 to override the teeth 49 while the sun gear 26 remains stationary during the left hand rotation of the motor too].

To accommodate the necessary overriding and axial shifting of the clutch disc 48, a connecting rod 51 is axially threaded (as indicated at 55 in the forward face of the input socket element 46. The connecting rod 51 extends axially forward through the clutch disc 28, through the tubular clutch shaft 27 and through the sun gear 26 into the interior of the drive fitting 31 where it terminates in a terminal nut 52 provided with a thrust bearing 53. A helical compression spring 54, compressed between two slidable spring washers 58, surrounds the connecting rod 51 and is in turn compressed between the forward extremity of the tubular clutch shaft 27 and the thrust bearing 53 so as to resiliently maintain the teeth 50 of the second clutch disc 48 in engagement with the teeth 49 of the first clutch disc 28 so that reverse rotation of the input socket element 46 can cause the teeth to override against the bias of the spring 54 as will be later described.

A spacing shim 57 is positioned between the flange 32 and the end wall 14 to limit the forward travel of compression rods 33 to the desired distance required by the particular nuts upon which the tool is to be used.

OPERATION Let us assume that the drive shank of a conventional reversable motor tool has been inserted in the tool receiving socket 56 of the input socket element 46 and that the nut socket member 16 has been positioned over the bolt B with the nut A of the latter in place in the nut socket 39, as shown in FIG. 7.

The motor tool is now started to the right and, since the nut presents a minimal of resistance, the entire tool assembly will rotate to the right to thread the nut forwardly on the bolt against the work pieces C.

When the nut encounters the resistance of the work pieces, rotation of the nut socket member 16 will tend to cease and the retaining pin 17 will eventually stop further rotation of the housing and its cap 12. The sun gear, however, will continue to rotate and the planet gears 24 will act as traction gears within the stationary ring gear causing the axes of the planet gears to orbit around the axis of the sun gear so as to cause the sleeve 22 to rotate at reduced speed and increased power about the stationary drive fitting 31 to cause the threads 29 and 30 to react to force the stationary drive fitting 31 and its compression rods 33 forwardly.

This forward motion is imparted by the rods 33 to the jaw cup 37 to force the conical lip 44 of the latter forwardly up the inclined crimping jaws 41 to urge the nut-indenting edges 45 axially inward against the cylindrical skirt D of the nut so as to form four equally spaced crimps or indentations E therein, as shown in FIG. 8. I

The crimping and indenting continues until the flange 32 on the drive fitting 22 contacts the end wall 14, or the spacing shim 57 positioned thereagainst. The latter contact stops rotation of the sun gear and stalls the motor tool in torsional contact with the nut A.

The motor tool is now reversed to cause the sun gear to rotate to the left to cause the planet gears to orbit in the opposite direction about the tool axis so as to rotate the sleeve 29 to the left to cause the threads 29 and 30 to relatively unscrew and move the jaw cup 37 rearwardly from the jaws 41 to allow the latter to expand and release the nut. The unscrewing will continue until the drive fitting 31, or its flange 32, contacts the sleeve 22, as shown in FIG. 1. When the latter contact occurs, rearward rotation of the sun gear 26 will be stopped and the teeth of the clutch discs 28 and 48 will override against the bias of the spring 54 to prevent the motor tool from unscrewing the crimped nut A. The overriding continues until the motor tool is shut off or the entire assembly is withdrawn from the nut A.

While a selected form of the invention has been above described, it is understood that mechanical variations and detail substitutions can be made by one skilled in the art without departing from the spirit of the invention.

Having thus described the invention what is claimed and desired to be secured by Letters Patent is:

1. A nut crimping tool for installing and crimping a nut upon a threaded bolt shank comprising:

a. a substantially cylindrical housing having an open rear extremity and provided with a fixed end wall at its forward extremity;

b. a cup-shaped jaw cup concentrically positioned on and forwardly of said end wall, said jaw cup being adapted to rotate with said housing and being axially movable toward and away from said wall;

c. a substantially cylindrical nut socket member fixedly mounted in said end wall and extending axially forward within said jaw cup to receive said bolt and said nut;

d. a plurality of crimping jaws hingedly mounted at their rear extremities on and about sad nut socket member within said jaw cup and projecting forward of both said nut socket member and said jaw cup;

e. means for simultaneously and resiliently flaring the forward extremities of said jaws diametrically outward from the projected axis of said nut socket member and inter- .nally against said jaw cup;

f. means for rotating said housing to cause said nut socket member to rotate therewith so as to torque said nut upon said bolt;

g. means for urging said jaw cup forwardly from said wall into contact with said flared jaws to urge the forward extremities of the latter inwardly into crimping relation with said nut.

2. A nut crimping tool as described in claim 1 in which the means for urging said jaw cup forwardly comprises:

a. a substantially cylindrical drive fitting concentrically positioned within said housing;

b. compression members mounted in said fitting and slidably extending forward through said end wall in radially spaced relation to the wall, said jaw cup being mounted on the forward extremities of said compression members forwardly of said wall; and

(1. means for urging said drive fitting forward to cause said compression members to carry said jaw cup forward against said jaws.

3. A nut crimping tool as described in claim 2 in which the means for urging the drive fitting forward comprises:

a. a substantially cylindrical rotatable, endwise immovable sleeve threaded upon said drive fitting within said housing; and

b. means for imparting rotation to said sleeve independently of the rotation of said housing to cause the sleeve to thread the drive fitting forwardly.

4. A nut crimping tool as described in claim 3 in which the means for imparting rotation to the sleeve comprises:

a. an internal ring gear in said housing;

b. a rotatable axially positioned sun gear positioned in said housing;

c. a series of planet gears intermeshed between said sun gear and said ring gear, the axes of said planet gears being joumaled in said sleeve so that orbital rotation of said planet gears will rotate said sleeve on said drive fitting to drive the latter forwardly; and

d. means for rotating said sun gear independently of the rotation of said housing.

5. A nut crimping tool as described in claim 4 in which the means for rotating said sun gear comprises:

a. a cap element closing the rear extremity of said housing;

b. an input socket element axially joumaled in said cap element; and

c. means for communicating rotation from said input socket element to said sun gear independently of rotation of said housing 6. A nut crimping tool as described in claim 5 in which the means for communicating rotation to said sun gear comprises:

a. a directional clutch mechanism interposed between said input socket element and said sun gear which will interengage to positively drive the sun gear when said socket element is rotated to the right and which will override to allow said sun gear to remain stationary when rotated to the left.

7. A nut crimping tool as described in claim 6 in which the directional clutch mechanism comprises:

a. a first series of radially positioned clutch teeth concentrically mounted on said sun gear rearwardly of the latter;

b. a second series of radially positioned clutch teeth concentrically mounted on the forward extremity of said input socket so as to be meshable with said first series;

c. an axially positioned connecting rod mounted in the forward extremity of said input socket and extending axially and freely forward through said sun gear into the interior of said drive fitting and terminating in a thrust bearing;

d. a compression spring surrounding said connecting rod, said spring being permanently compressed between said sun gear and said thrust bearing to cause said connecting rod to resiliently draw the second series of teeth into engagement with the first series of teeth, said teeth being cooperatively inclined to positively drive the sun gear when said socket element is right rotated and to override when said socket element is left rotated.

8. A nut crimping tool as described in claim 2 having:

a. a circumferential groove formed in said nut socket member within said jaw cup;

b. an axially extending latch projection at the inner extremity of each crimping jaw;

c. a spring ring surrounding all of said inner extremities acting to urge said latching projections into said circumferential groove to cause the forward extremities to flare outwardly against the inside of the lip of said jaw cup when said jaw cup is moved rearwardly; and

d. an axially extending nut-indenting edge formed on the outer extremity of each jaw adapted to be impressed into said nut when said jaw cup is moved forwardly thereon. 

1. A nut crimping tool for installing and crimping a nut upon a threaded bolt shank comprising: a. a substantially cylindrical housing having an open rear extremity and provided with a fixed end wall at its forward extremity; b. a cup-shaped jaw cup concentrically positioned on and forwardly of said end wall, said jaw cup being adapted to rotate with said housing and being axially movable toward and away from said wall; c. a substantially cylindrical nut socket member fixedly mounted in said end wall and extending axially forward within said jaw cup to receive said bolt and said nut; d. a plurality of crimping jaws hingedly mounted at their rear extremities on and about sad nut socket member within said jaw cup and projecting forward of both said nut socket member and said jaw cup; e. means for simultaneously and resiliently flaring the forward extremities of said jaws diametrically outward from the projected axis of said nut socket member and internally against said jaw cup; f. means for rotating said housing to cause said nut socket member to rotate therewith so as to torque said nut upon said bolt; g. means for urging said jaw cup forwardly from said wall into contact with said flared jaws to urge the forward extremities of the latter inwardly into crimping relation with said nut.
 2. A nut crimping tool as described in claim 1 in which the means for urging said jaw cup forwardly comprises: a. a substantially cylindrical drive fitting concentrically positioned within said housing; b. compression members mounted in said fitting and slidably extending forward through said end wall in radially spaced relation to the wall, said jaw cup being mounted on the forward extremities of said compression members forwardly of said wall; and d. means for urging said drive fitting forward to cause said compression members to carry said jaw cup forward against said jaws.
 3. A nut crimping tool as described in claim 2 in which the means for urging the drive fitting forward comprises: a. a substantially cylindrical rotatable, endwise Immovable sleeve threaded upon said drive fitting within said housing; and b. means for imparting rotation to said sleeve independently of the rotation of said housing to cause the sleeve to thread the drive fitting forwardly.
 4. A nut crimping tool as described in claim 3 in which the means for imparting rotation to the sleeve comprises: a. an internal ring gear in said housing; b. a rotatable axially positioned sun gear positioned in said housing; c. a series of planet gears intermeshed between said sun gear and said ring gear, the axes of said planet gears being journaled in said sleeve so that orbital rotation of said planet gears will rotate said sleeve on said drive fitting to drive the latter forwardly; and d. means for rotating said sun gear independently of the rotation of said housing.
 5. A nut crimping tool as described in claim 4 in which the means for rotating said sun gear comprises: a. a cap element closing the rear extremity of said housing; b. an input socket element axially journaled in said cap element; and c. means for communicating rotation from said input socket element to said sun gear independently of rotation of said housing.
 6. A nut crimping tool as described in claim 5 in which the means for communicating rotation to said sun gear comprises: a. a directional clutch mechanism interposed between said input socket element and said sun gear which will interengage to positively drive the sun gear when said socket element is rotated to the right and which will override to allow said sun gear to remain stationary when rotated to the left.
 7. A nut crimping tool as described in claim 6 in which the directional clutch mechanism comprises: a. a first series of radially positioned clutch teeth concentrically mounted on said sun gear rearwardly of the latter; b. a second series of radially positioned clutch teeth concentrically mounted on the forward extremity of said input socket so as to be meshable with said first series; c. an axially positioned connecting rod mounted in the forward extremity of said input socket and extending axially and freely forward through said sun gear into the interior of said drive fitting and terminating in a thrust bearing; d. a compression spring surrounding said connecting rod, said spring being permanently compressed between said sun gear and said thrust bearing to cause said connecting rod to resiliently draw the second series of teeth into engagement with the first series of teeth, said teeth being cooperatively inclined to positively drive the sun gear when said socket element is right rotated and to override when said socket element is left rotated.
 8. A nut crimping tool as described in claim 2 having: a. a circumferential groove formed in said nut socket member within said jaw cup; b. an axially extending latch projection at the inner extremity of each crimping jaw; c. a spring ring surrounding all of said inner extremities acting to urge said latching projections into said circumferential groove to cause the forward extremities to flare outwardly against the inside of the lip of said jaw cup when said jaw cup is moved rearwardly; and d. an axially extending nut-indenting edge formed on the outer extremity of each jaw adapted to be impressed into said nut when said jaw cup is moved forwardly thereon. 